Electrical insulator



(No Model.)

D. M..STEWARD.

ELEOTRIGAL INSULATOR. No. 271,994. Patented Feb. 6, 1883.

WITNESSES INVENTOR ATTORNEY-S.

N4 PETERS. Phalo-Lilhogn hr. wammm. c.

UNITED STATES PATENT OFFICE.

DEMETRIUS M. STEWARD, OF CINCINNATI, OHIO.

ELiECTRiCAL INSULATOR.

SPECIFICATION forming part of Letters Patent No. 271,994, dated February6, 1883, Application filed August 522, 1882. (No model.)

To all whom it may concern:

Be it known that I, DEMETRIUS M. STEW- ARD, of Cincinnati, Hamiltoncounty, and State of Ohio, have invented a new and Improved ElectricInsulator, of which the following is Qfull, clear, and exactdescription.

My invention relates to improvements in electrical insulators; and itconsists in the process of treating steatite, as hereinafter fullydescribed, and pointed out in the claims.

Reference is to be had to the accompanying drawings, forming part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure l is a perspective view of a piece of wire or cable provided withmy improved insulator. Fig. 2 is a cross-sectional elevation of aninsulating-disk, which is used to insulate a Wire or cable at certainpoints; and Fig. 3 is a longitudinal elevation of an insulatingsleevefor insulating a wire in a door or window frame or casing. I

For the purpose of insulating electric wires, I surround them throughouttheir length, or at points at which they are to be insulated, with alayer of steatite, which is used in its hardened stateas artificiallava-made by hardening it by treatment with ammonia and muriatic acid insolution, and then subjecting it to heat in aretort, or in any mannerpreferred which will accomplish the desired result. The powderedsteatite may be mixed with plaster-of-paris and liquids to form amortar, and can then be molded into shape; or it may be cut, turned, orotherwise made of convenient shapes and sizes, wherever an insulator isrequired for electric light or motor wires-forinstance,'as insulatingtubes, rings, sleeves, or as a saddle, or as a block, with transverseapertures for crossed wires. The tubes are made in sections, and aresuccessively passed over the wire and the sections joined together byacement, in case the entire wire is to be insulated in the interior of abuilding; or the electric wire can be packed in and surrounded bypowdered steatite, which is held on the wire by a woven tube of cottonor other suitable material.

Underground wires can be insulated by packing them in a mortar made withpowdered steatite. The insulating layer may have any desired thickness.It can also be applied on the wires as a wash or paint, and afterseveral coats of this wash have been applied an insuhting layer ofsteatite will be formed on the wires.

In Fig. l, A is the wire; B, the insulatingtube, made of steatite.

In case the wire A, Fig. 2, must pass through a partition or the floor,or a support, a ring, C, of steatite is secured in this floor orpartition, and the wire A is passed through this ring.

In place of the ring C, a sleeve or collar, D, may be used, and this maybe provided with a circular ridge, E, to hold it in proper position in adoor or window casing, partition, &c.

The insulating material may be pressed, formed, or molded, turned, out,or otherwise made into any shape, as the circumstances may require. Theinsulators made of steatite or artificial lava are very hard anddurable, and are not affected by moisture, heat, or frost, oils, gases,acids, or other solvents, nor by any sudden change of temperature, asthe heat of a burning building, and are thus far superior to glass andrubber insulators, for the former are very apt to break, and the latterare expensive and liable to crack.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The process herein described of treating steatiteto form electrical insulators, consisting in treating it with ammoniaand muriatic acid, and then subjecting it to heat, as set forth.

2. The process herein described of treating steatite to form electricalinsulators, consisting in treating it with ammonia and inuriatic acid,subjecting it to the heat, mixing it with plaster-of-paris and liquidsto form a mortar, and finally forming it into suitable shapes, asdescribed.

DEMETRIUS M. STEWARD.

Witnesses Gems. SWARTZENBURG, CLIFFORD STEWARD.

